(19)

(11)

EP 1 787 331 A2

(12)

(43) Date of publication: 23.05.2007 Bulletin 2007/21 (21) Application number: 05725829.5 (22) Date of filing: 18.03.2005

(51) International Patent Classification (IPC):  H01L 29/423(2006.01) (86) International application number: PCT/US2005/008940 (87) International publication number: WO 2005/089440 (29.09.2005 Gazette 2005/39)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR Designated Extension States: AL BA HR LV MK YU (30) Priority: 18.03.2004 US 708674 (71) Applicant: International Business Machines Corporation Armonk, NY 10504 (US)	(72) Inventors: CLARK, William, F., Jr. Essex Junction, VT 05452 (US) NOWAK, Edward, J. Essex Junction, VT 05452 (US) (74) Representative: Williams, Julian David  IBM United Kingdom Limited Intellectual Property Law Hursley Park Winchester Hampshire SO21 2JN Winchester Hampshire SO21 2JN (GB)